I need help building a custom metal detector. The device consists of two FG+3 sensors, an ADS1015 analog unit, a power supply unit with a 5V charging step-up, an ESP32WOORM, a headset, a power button, a push button, an RG LED, and an FTF spi 240X320 1.2V 2.8 touch screen. What is the distance between the lower and upper sensors? What are your tips on how to build this project and the correct programming? Thank you.